/**
 * Copyright 2012 Gerardo Cortes Oquendo.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * See the License for the specific language governing permissions and 
 * limitations under the License.
 */
package co.pixellabs.gear.util;

/**
 * @author gerardo.cortes.o@gmail.com
 * 
 */
public final class Id<T extends Comparable<T>> implements Comparable<Id<T>>
{
    private static final int CLASS_ID;
    private static final int PRIME;
    private final T id;
    private final int hashCode;

    static
    {
	CLASS_ID = -1;
	PRIME = 31;
    }

    public static final <T extends Comparable<T>> Id<T> of(final T id)
    {
	return new Id<T>(id);
    }

    private Id(final T id)
    {
	this.id = id;
	this.hashCode = computeHashCode();
    }

    private final int computeHashCode()
    {
	return CLASS_ID * PRIME + id.hashCode();
    }

    public final T getValue()
    {
	return id;
    }

    @Override
    public int hashCode()
    {
	return hashCode;
    }

    @Override
    public boolean equals(Object obj)
    {
	return (this == obj) || ((obj instanceof Id) && ((Id<?>) obj).id.equals(id));
    }

    @Override
    public int compareTo(Id<T> obj)
    {
	return id.compareTo(obj.id);
    }

    @Override
    public String toString()
    {
	return "Id [id=" + id + "]";
    }

}
